/* OK, now commit destination to socket. */
sk_setup_caps(sk, &rt->u.dst);
- dp->dccps_gar =
- dp->dccps_iss = secure_dccp_sequence_number(inet->saddr,
- inet->daddr,
- inet->sport,
- usin->sin_port);
- dccp_update_gss(sk, dp->dccps_iss);
-
+ dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, inet->daddr,
+ inet->sport, inet->dport);
inet->id = dp->dccps_iss ^ jiffies;
err = dccp_connect(sk);
sock_put(sk);
}
-/* This routine computes an IPv4 DCCP checksum. */
-void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
+static inline u16 dccp_v4_csum_finish(struct sk_buff *skb,
+ __be32 src, __be32 dst)
+{
+ return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
+}
+
+void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
{
const struct inet_sock *inet = inet_sk(sk);
struct dccp_hdr *dh = dccp_hdr(skb);
- dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr, inet->daddr);
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, inet->saddr, inet->daddr);
}
EXPORT_SYMBOL_GPL(dccp_v4_send_check);
-static inline u64 dccp_v4_init_sequence(const struct sock *sk,
- const struct sk_buff *skb)
+static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
{
return secure_dccp_sequence_number(skb->nh.iph->daddr,
skb->nh.iph->saddr,
return sk;
}
-int dccp_v4_checksum(const struct sk_buff *skb, const __be32 saddr,
- const __be32 daddr)
-{
- const struct dccp_hdr* dh = dccp_hdr(skb);
- int checksum_len;
- u32 tmp;
-
- if (dh->dccph_cscov == 0)
- checksum_len = skb->len;
- else {
- checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
- checksum_len = checksum_len < skb->len ? checksum_len :
- skb->len;
- }
-
- tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
- return csum_tcpudp_magic(saddr, daddr, checksum_len,
- IPPROTO_DCCP, tmp);
-}
-
-EXPORT_SYMBOL_GPL(dccp_v4_checksum);
-
-static int dccp_v4_verify_checksum(struct sk_buff *skb,
- const __be32 saddr, const __be32 daddr)
-{
- struct dccp_hdr *dh = dccp_hdr(skb);
- int checksum_len;
- u32 tmp;
-
- if (dh->dccph_cscov == 0)
- checksum_len = skb->len;
- else {
- checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
- checksum_len = checksum_len < skb->len ? checksum_len :
- skb->len;
- }
- tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
- return csum_tcpudp_magic(saddr, daddr, checksum_len,
- IPPROTO_DCCP, tmp) == 0 ? 0 : -1;
-}
-
static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
struct sk_buff *skb)
{
const struct inet_request_sock *ireq = inet_rsk(req);
struct dccp_hdr *dh = dccp_hdr(skb);
- dh->dccph_checksum = dccp_v4_checksum(skb, ireq->loc_addr,
- ireq->rmt_addr);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
+ ireq->rmt_addr);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
ireq->rmt_addr,
ireq->opt);
- if (err == NET_XMIT_CN)
- err = 0;
+ err = net_xmit_eval(err);
}
out:
return err;
}
-static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
+static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
{
int err;
struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
sizeof(struct dccp_hdr_reset);
struct sk_buff *skb;
struct dst_entry *dst;
- u64 seqno;
+ u64 seqno = 0;
/* Never send a reset in response to a reset. */
if (rxdh->dccph_type == DCCP_PKT_RESET)
DCCP_SKB_CB(rxskb)->dccpd_reset_code;
/* See "8.3.1. Abnormal Termination" in RFC 4340 */
- seqno = 0;
if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
dccp_hdr_set_seq(dh, seqno);
- dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
- DCCP_SKB_CB(rxskb)->dccpd_seq);
+ dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
- dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr,
- rxskb->nh.iph->daddr);
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, rxskb->nh.iph->saddr,
+ rxskb->nh.iph->daddr);
bh_lock_sock(dccp_v4_ctl_socket->sk);
err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
rxskb->nh.iph->saddr, NULL);
bh_unlock_sock(dccp_v4_ctl_socket->sk);
- if (err == NET_XMIT_CN || err == 0) {
+ if (net_xmit_eval(err) == 0) {
DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
}
ireq = inet_rsk(req);
ireq->loc_addr = skb->nh.iph->daddr;
ireq->rmt_addr = skb->nh.iph->saddr;
- req->rcv_wnd = dccp_feat_default_sequence_window;
ireq->opt = NULL;
/*
*/
dreq = dccp_rsk(req);
dreq->dreq_isr = dcb->dccpd_seq;
- dreq->dreq_iss = dccp_v4_init_sequence(sk, skb);
+ dreq->dreq_iss = dccp_v4_init_sequence(skb);
dreq->dreq_service = service;
if (dccp_v4_send_response(sk, req, NULL))
/*
* Step 3: Process LISTEN state
- * If S.state == LISTEN,
- * If P.type == Request or P contains a valid Init Cookie
- * option,
- * * Must scan the packet's options to check for an Init
- * Cookie. Only the Init Cookie is processed here,
- * however; other options are processed in Step 8. This
- * scan need only be performed if the endpoint uses Init
- * Cookies *
- * * Generate a new socket and switch to that socket *
- * Set S := new socket for this port pair
- * S.state = RESPOND
- * Choose S.ISS (initial seqno) or set from Init Cookie
- * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
- * Continue with S.state == RESPOND
- * * A Response packet will be generated in Step 11 *
- * Otherwise,
- * Generate Reset(No Connection) unless P.type == Reset
- * Drop packet and return
+ * If P.type == Request or P contains a valid Init Cookie option,
+ * (* Must scan the packet's options to check for Init
+ * Cookies. Only Init Cookies are processed here,
+ * however; other options are processed in Step 8. This
+ * scan need only be performed if the endpoint uses Init
+ * Cookies *)
+ * (* Generate a new socket and switch to that socket *)
+ * Set S := new socket for this port pair
+ * S.state = RESPOND
+ * Choose S.ISS (initial seqno) or set from Init Cookies
+ * Initialize S.GAR := S.ISS
+ * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
+ * Continue with S.state == RESPOND
+ * (* A Response packet will be generated in Step 11 *)
+ * Otherwise,
+ * Generate Reset(No Connection) unless P.type == Reset
+ * Drop packet and return
*
* NOTE: the check for the packet types is done in
* dccp_rcv_state_process
return 0;
reset:
- dccp_v4_ctl_send_reset(skb);
+ dccp_v4_ctl_send_reset(sk, skb);
discard:
kfree_skb(skb);
return 0;
EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
+/**
+ * dccp_invalid_packet - check for malformed packets
+ * Implements RFC 4340, 8.5: Step 1: Check header basics
+ * Packets that fail these checks are ignored and do not receive Resets.
+ */
int dccp_invalid_packet(struct sk_buff *skb)
{
const struct dccp_hdr *dh;
+ unsigned int cscov;
if (skb->pkt_type != PACKET_HOST)
return 1;
+ /* If the packet is shorter than 12 bytes, drop packet and return */
if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
LIMIT_NETDEBUG(KERN_WARNING "DCCP: pskb_may_pull failed\n");
return 1;
dh = dccp_hdr(skb);
- /* If the packet type is not understood, drop packet and return */
+ /* If P.type is not understood, drop packet and return */
if (dh->dccph_type >= DCCP_PKT_INVALID) {
LIMIT_NETDEBUG(KERN_WARNING "DCCP: invalid packet type\n");
return 1;
}
/*
- * If P.Data Offset is too small for packet type, or too large for
- * packet, drop packet and return
+ * If P.Data Offset is too small for packet type, drop packet and return
*/
if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
- "too small 1\n",
- dh->dccph_doff);
+ "too small\n", dh->dccph_doff);
return 1;
}
-
+ /*
+ * If P.Data Offset is too too large for packet, drop packet and return
+ */
if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
- "too small 2\n",
- dh->dccph_doff);
+ "too large\n", dh->dccph_doff);
return 1;
}
- dh = dccp_hdr(skb);
-
/*
* If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
* has short sequence numbers), drop packet and return
*/
- if (dh->dccph_x == 0 &&
- dh->dccph_type != DCCP_PKT_DATA &&
- dh->dccph_type != DCCP_PKT_ACK &&
- dh->dccph_type != DCCP_PKT_DATAACK) {
- LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data, Ack "
- "nor DataAck and P.X == 0\n",
+ if (dh->dccph_type >= DCCP_PKT_DATA &&
+ dh->dccph_type <= DCCP_PKT_DATAACK && dh->dccph_x == 0) {
+ LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data||Ack||"
+ "DataAck, while P.X == 0\n",
dccp_packet_name(dh->dccph_type));
return 1;
}
+ /*
+ * If P.CsCov is too large for the packet size, drop packet and return.
+ * This must come _before_ checksumming (not as RFC 4340 suggests).
+ */
+ cscov = dccp_csum_coverage(skb);
+ if (cscov > skb->len) {
+ LIMIT_NETDEBUG(KERN_WARNING
+ "DCCP: P.CsCov %u exceeds packet length %d\n",
+ dh->dccph_cscov, skb->len);
+ return 1;
+ }
+
+ /* If header checksum is incorrect, drop packet and return.
+ * (This step is completed in the AF-dependent functions.) */
+ skb->csum = skb_checksum(skb, 0, cscov, 0);
+
return 0;
}
{
const struct dccp_hdr *dh;
struct sock *sk;
+ int min_cov;
- /* Step 1: Check header basics: */
+ /* Step 1: Check header basics */
if (dccp_invalid_packet(skb))
goto discard_it;
- /* If the header checksum is incorrect, drop packet and return */
- if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
- skb->nh.iph->daddr) < 0) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: incorrect header checksum\n",
+ /* Step 1: If header checksum is incorrect, drop packet and return */
+ if (dccp_v4_csum_finish(skb, skb->nh.iph->saddr, skb->nh.iph->daddr)) {
+ LIMIT_NETDEBUG(KERN_WARNING
+ "%s: dropped packet with invalid checksum\n",
__FUNCTION__);
goto discard_it;
}
/*
* Step 2:
* If no socket ...
- * Generate Reset(No Connection) unless P.type == Reset
- * Drop packet and return
*/
if (sk == NULL) {
dccp_pr_debug("failed to look up flow ID in table and "
goto no_dccp_socket;
}
+ /*
+ * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
+ * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
+ * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
+ */
+ min_cov = dccp_sk(sk)->dccps_pcrlen;
+ if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
+ dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
+ dh->dccph_cscov, min_cov);
+ /* FIXME: "Such packets SHOULD be reported using Data Dropped
+ * options (Section 11.7) with Drop Code 0, Protocol
+ * Constraints." */
+ goto discard_and_relse;
+ }
+
if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_and_relse;
nf_reset(skb);
goto discard_it;
/*
* Step 2:
+ * If no socket ...
* Generate Reset(No Connection) unless P.type == Reset
* Drop packet and return
*/
if (dh->dccph_type != DCCP_PKT_RESET) {
DCCP_SKB_CB(skb)->dccpd_reset_code =
DCCP_RESET_CODE_NO_CONNECTION;
- dccp_v4_ctl_send_reset(skb);
+ dccp_v4_ctl_send_reset(sk, skb);
}
discard_it:
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff